1. Field of the Invention
The present invention generally relates to printer technology, and particularly to technology of processing control based on a specific command system used for the communication between a host device and printer.
2. Description of the Related Art
In order for a host device, as typified by a PC, to make a printer print application data, the host device requires a printer driver (program for controlling the printer) prepared for each printer. Upon receiving application data from an application program, the printer driver converts such application data into print job data unique to the printer and outputs this to such printer. When the printer receives this application data, it interprets this and generates bit map data in a raster format and thereby realizes printing on printing paper.
Further, in a typical information processing system, electronic devices such as a printer, scanner, digital camera and so on are peripherally arranged with the host device in the center. The host device having built-in drivers (device drivers) unique to the respective electronic devices intermediates information with such electronic devices. For example, when printing image data stored in a digital camera, the host device initially reads the image data stored in this digital camera into the application program, converts this image data into print job data via the printer driver from the application data, and outputs this to the printer.
The program size of the printer driver is ordinarily several hundred K Bytes or more. Therefore, host devices such as computers having superior processing speed and abundant memory space will have no problems being provided with built-in printer drivers. Nevertheless, with small electronic devices such as a digital camera, for example, it is difficult to provide built-in printer drivers due to hardware restrictions and so forth.
Accordingly, an object of the present invention is to enable a host device to make a printer print document data in the host device without requiring conventional printer drivers.
Another object of the present invention is to provide a novel communication protocol between the host device and printer based on a specific command system.